The atomic fact: the C programming language was created by Dennis Ritchie at Bell Labs, with its key development occurring around 1972. The source for this is Ritchie’s own history of the language, “The Development of the C Language.”
In that paper Ritchie writes that C “came into being in the years 1969-1973, in parallel with the early development of the Unix operating system,” and that “the most creative period occurred during 1972.” This is why 1972 is the year most commonly attached to the creation of C, even though the language evolved over several years rather than appearing all at once.
The same account places the work at Bell Labs in Murray Hill, New Jersey, on a small DEC PDP-11, and ties C closely to the Unix system for which it was built.